The present invention relates to a photochemical reactor for performing photochemical reactions, and, more particularly, to a photochemical reactor comprising a reaction vessel transparent to radiation for receiving the substances to be irradiated, a UV-radiation source, and luminescent materials which transform the UV-light of the radiation source into a specific wavelength, characteristic of the luminescent material which effects the photochemical reactions of the substances.
In known reactors of this construction, the radiation sources employed are low pressure mercury lamps whose envelopes are coated with luminescent material. Depending on the desired wavelength, lamps with different luminescent coatings are used. These lamps, however, have only a limited lifetime because the luminescent materials decrease in their radiative efficiency after a certain operation time as a consequence of electrode vaporization. In addition, high cooling power is required for these lamps because the luminescent materials operate optimally only at the relatively low temperature of approximately 20.degree. C.